球磨处理对大米淀粉理化性质的影响

为了扩大大米淀粉的应用范围,对其进行球磨处理,并分析不同转速条件下球磨处理对大米淀粉理化性质的影响。结果表明,随着球磨转速的加大,大米淀粉颗粒形态被破坏的程度越大;球磨能使大米淀粉分子链发生断裂,导致还原糖含量增加;大米淀粉的冷水溶解度与球磨转速正相关,球磨处理程度较高的大米淀粉几乎冷水可溶;球磨处理使大米淀粉的成糊温度、峰值黏度和最终黏度降低,淀粉糊的稳定性提高。     

用RVA仪分析玉米淀粉的糊化特性

以玉米淀粉为原料,利用RVA(快速黏度分析仪),研究了不同浓度玉米淀粉以及在同一浓度下氯化钠、蔗糖以及转速对淀粉糊化特性的影响,并且在此基础上将RVA糊化程序改为多重RVA程序,然后观察对淀粉的特性的影响。结果表明:随着玉米淀粉溶液浓度的增加,起始成糊温度降低,淀粉糊的热稳定性降低,凝胶性增强。随氯化钠浓度增大,起始成糊温度逐渐升高,到达峰值时间有所延长,热稳定性明显提高,但凝胶性降低。当蔗糖浓度增加时,淀粉成糊温度、峰值黏度、最低黏度和最终黏度都随之增加,热稳定性增强,冷却过程中淀粉糊形成凝胶的能力减弱。玉米淀粉在多重RVA程序中,淀粉胶体反复形成并且溶解。添加油脂后的玉米淀粉的黏度曲线的变化是复杂的,由淀粉和油脂之间的相互作用引起,油脂的水溶性以及淀粉颗粒与蛋白质的关系影响着它们的相互反应。     

球磨对绿豆淀粉颗粒形态和理化性质的影响

采用行星式球磨机对绿豆淀粉进行改性研究,以球磨时间为控制变量,对比球磨0、1、2、4、6h时绿豆淀粉颗粒形态和淀粉糊理化性质的变化.结果表明,球磨处理后绿豆淀粉颗粒表面出现凹痕,表皮变皱逐渐破裂,随时间的增加颗粒变得扁平并有抱团现象,偏光十字逐渐模糊直至消失;随球磨时间的延长,损伤淀粉和直链淀粉含量增加,淀粉糊溶解度、透明度和析水率均显著增大,淀粉糊峰值黏度、谷值黏度、最终黏度、回生值和衰减值均呈下降趋势.     

微细化莲子淀粉的流变特性研究

本实验以球磨粉碎后的莲子淀粉为研究对象,研究粉碎时间、淀粉糊浓度、温度对微细化莲子淀粉糊流变特性的影响。结果表明：莲子淀粉糊为假塑性流体,球磨时间对莲子淀粉糊的表观黏度有显著影响;莲子淀粉糊的表观黏度随着浓度的增加迅速增大,剪切速率越低,这种影响就越明显,但球磨时间达到96h后,浓度对表观黏度变化影响不大;温度对莲子淀粉的流变特性影响显著,随着温度的增加,表观黏度迅速增大,但是经过长时间球磨后的莲子淀粉糊的流变特性对温度的依赖性减小。     

机械球磨对绿豆淀粉糊性质的影响

利用球磨处理对绿豆淀粉进行机械损伤,研究球磨对绿豆淀粉糊性质的影响。结果表明:随着球磨时间的增加,绿豆淀粉中损伤淀粉含量显著增加,且透明度、溶解度和膨润力呈现上升趋势;糊化特性的测定结果显示:峰值黏度、谷值黏度、最终黏度、回生值和糊化温度都随着球磨处理时间的增加而降低;且球磨对淀粉的凝胶特性也有一定的影响,其中硬度和脆度均与球磨处理时间呈极显著负相关关系。     

追氮对夏玉米淀粉含量及其糊化特性的影响

以郑单958为材料,研究玉米随追氮量增加玉米籽粒淀粉含量、淀粉相关酶活性及其淀粉糊化特性的影响,研究结果表明玉米籽粒淀粉及直链淀粉含量随追氮量的增加先升高后略有下降;腺苷二磷酸葡萄糖焦磷酸化酶(ADPG-PPase)、尿苷二磷酸葡萄糖焦磷酸化酶(UDPG-PPase)及束缚态淀粉合成酶(GBSS)的活性随追氮量的增加先升高后降低。可溶性淀粉合成酶(SSS)的活性随追氮量的增加先降低后升高;随追氮量的增加淀粉的峰值黏度、低谷黏度、最终黏度及崩解值先升高后降低,峰值时间以及糊化温度先降低后升高。     

荸荠淀粉糊粘度特性研究

测定了荸荠淀粉糊的Brabender 黏度曲线,利用NDJ-8S数字显示黏度计研究了淀粉乳浓度、pH值、增稠剂、糖、盐等因素对荸荠淀粉糊黏度的影响以及荸荠淀粉糊的流变性。实验结果表明,荸荠淀粉糊化温度低,峰值黏度大,冷稳定性优良,不易发生老化,但热稳定性差。荸荠淀粉糊的黏度随淀粉浓度增加而呈幂次方上升;酸使糊黏度下降,碱使糊黏度上升;黄原胶与魔芋胶均使淀粉糊的黏度增加;葡萄糖和蔗糖对糊黏度的影响呈现先上升后下降的趋势;NaCl与CaCl2均能降低淀粉糊的黏度。荸荠淀粉糊属于非牛顿假塑性流体。     

芒果皮粉对淀粉糊化与老化特性的影响

采用布拉班德黏度仪、差示扫描量热仪等测定芒果皮粉的添加对玉米淀粉和大米淀粉黏度、热特性、透光率、沉降率、凝胶硬度与色泽的影响。结果表明,随芒果皮粉添加量(0%~15%)的增加,2种淀粉的起糊温度逐渐降低,玉米淀粉糊峰值黏度在添加15%芒果皮粉时显著升高,崩解值增大;大米淀粉糊峰值黏度呈降低趋势,崩解值先降低后升高,2种淀粉回生值都显著降低。芒果皮粉的添加显著降低了2种淀粉的糊化和老化焓值及贮藏中透光率与沉降率的下降程度,减小玉米淀粉凝胶的硬度,降低了2种淀粉凝胶色泽的变化程度。说明芒果皮粉的添加影响淀粉的糊化特性,且影响趋势随淀粉品种不同而异,但能有效抑制2种淀粉的老化。     

不同食品成分对红薯淀粉糊黏度特性的影响

利用快速粘度分析仪分析了不同食品成分,如淀粉乳浓度、氯化钠、蔗糖、明矾、玉米淀粉对红薯淀粉糊黏度特性的影响,结果表明:随着红薯淀粉浓度的增加,其淀粉糊峰值黏度提高,回生性增强;氯化钠使红薯淀粉糊的峰值黏度下降,蔗糖则使红薯淀粉糊的峰值黏度升高,二者均能增强淀粉糊的回生性;明矾对红薯淀粉糊峰值黏度影响较大,对其回生性影响较小;玉米淀粉可以使红薯淀粉糊的最终黏度升高,回生性增强.     

氧化蜡质玉米淀粉的糊流变特性研究

探讨了氧化蜡质玉米淀粉糊流变性、抗剪切能力以及浓度、温度和剪切速率对表观黏度的影响,并与蜡质玉米淀粉糊进行比较.结果表明:氧化蜡质玉米淀粉糊属于非牛顿流体.浓度、温度、剪切速率对流变性均有影响:在同一浓度和剪切速率下,表观黏度随温度的增加而减小;在同一温度和浓度条件下,淀粉糊的表现黏度随剪切速率的增加而减小;在室温、相同剪切速率下,表现黏度随浓度的增加而增大.氧化蜡质玉米淀粉糊属于剪切稀化体系,抗剪切能力较强.     

黄原胶对玉米淀粉糊化性能的影响

将黄原胶引入到淀粉浆料中,采用快速黏度分析法(RVA)研究了黄原胶的加入对玉米淀粉糊化性能和浆液表观黏度的影响,讨论了黄原胶与玉米淀粉分子之间的相互作用.结果表明:黄原胶可促进淀粉糊化,降低淀粉的糊化温度,缩短糊化时间;随着黄原胶质量分数的增加,淀粉的糊化峰值黏度增加,表现了2种高分子的相互作用;黏度衰减值随黄原胶增加...     

球磨改性淀粉制备交联淀粉的研究

研究了以水为介质湿法球磨后淀粉的结晶性、糊化特性、粒度分布,并考察了不同反应体系中球磨淀粉的反应效率.实验结果表明,球磨作用后淀粉结晶性部分破坏,糊化温度下降,平均粒径上升.在NaOH溶液和Na2cO3溶液两种体系中,淀粉的交联效率较低,球磨后的淀粉交联后含磷量相对交联原淀粉略低.在NaCl与Na2CO3混合体系中,淀粉的交联效果较好,球磨淀粉交联后舍磷量要高于交联原淀粉.     

Structural Change of Maize Starch Granules by Ball-mill Treatment

Effect of ball-mill treatment on physical properties and molecular change of maize starch granule was investigated. Ball-mill treatment was done by rotary type mill, and species of maize starch are normal, waxy and high amylose (amylo). Running time of the treatment is 0–320 h. Starch granules loss smoothness on surface and became rough, even though their changing speed was different among the three species. But, they retained whole figure and size after 320 h treatment in the all cases. Amylase susceptivity and water absorption activity were measured. Structural change of starch components was compared among the three species with X-ray diffraction, DSC and GPC. High Performance An-ion Exchange Chromatography (HPAEC) pattern of debranched sample treated with ball-mill for 320 h showed that formation of very short chain in amylopectin is little. ¹³C solid-NMR spectra suggest that disruption of molecules of amylopectin and amylose with ball-mill might occur at their glycosidic linkage. However, very slight radical was observed by Electron Spin Resonance spectroscopy (ESR) in the case of 320 h sample.     

Studies on Sweet Potatoes. Part II: Isolation and Characterization of Starch

By differential sedimentation and centrifugation steps four starch isolates were recovered from sun dried sweet potato flour. The granules in these isolates were of different size, shape and population characteristics, and were anionic in nature. They showed a single stage swelling with 30 to 35% solubility in water and only ∼30% solubility in DMSO even after 72h. Their starch content varied from ∼48 to 88%. The presence of thermostable amylases in sweet potato resulted in considerable decrease in Brabender viscosity values as amylographic studies in the presence of H_gCl₂ showed significant increase in peak (PV) and setback (SBV) viscosities. The starch isolate I had 25% higher PV as compared to the isolate II but retrogradation was much low in this. Susceptibility to glucoamylase digestion showed a decreasing trend from the isolate I to the IV on solid basis, but comparable on starch basis.     

Effect of Heat-Moisture Treatment and Acid Modification on Rheological, Textural, and Differential Scanning Calorimetry Characteristics of Sweetpotato Starch

Sweetpotato starches were characterized to understand the changes upon modification by acid and heat‐moisture treatment (HMT) in the rheological, differential scanning calorimetry (DSC), and textural characteristics of starch isolated from the sweetpotato variety PSP‐21 and to compare these findings with those of commercially available arrowroot starch. The native sweetpotato starch had a Type A pasting profile characterized by a high peak viscosity (PV) (741.5 rapid viscoanalyzer unit [rvu]), with a high breakdown (378.8 rvu) and low cold paste viscosity (CPV) (417.6 rvu). After HMT, there was a marked decrease in the PV (639.1), a very slight breakdown (113.5 rvu) and an increase in CPV (759.5 rvu), more like a Type C pasting profile. However, acid modification did not notably change the pasting profile of native sweetpotato starch. The DSC characteristics were also affected significantly after modifications. The gelatinization temperature parameter to onset (T_o) decreased significantly after HMT and acid modification. The gelatinization enthalpy decreased during HMT from 15.98 to 14.42 J/g. The gel strength of acid‐modified starch was the highest compared with that of HMT and native sweetpotato and arrowroot starches.     

Structural changes induced by high speed jet on in vitro digestibility and hydroxypropylation of rice starch

Influences of high speed jet (HSJ) at different pressures (0, 80, 160, 250 MPa) on digestibility and hydroxypropylation of rice starch were evaluated. HSJ treatment increased the content of rapidly digestible starch and slowly digestible starch and decreased the content of resistant starch with increasing of the treatment pressure in native starch. The degree and the reaction efficiency of hydroxypropylation of rice starch increased with an increase in treatment pressure. Scanning electron microscopy and X‐ray diffraction analysis showed that both the crystalline structure and the overall granular structure were partially destroyed. Meanwhile, HSJ treatment led to degradation of starch molecules. The results suggested that the changes of starch structure resulted in decreasing gelatinisation enthalpy of rice starch and might be response for the changes of reactivity and its digestibility to some extent.     

Micronization and Hydrophobic Modification of Cassava Starch

In this study, the cassava starch was micronized in a vacuum ball-mill to make tiny granules of different particle sizes (the d ₅₀ value from 7.9 μm to 24.0 μm). The properties of the micronized cassava starch, such as granularity, gelatinization properties, and dispersibility in organic solvent, have been evaluated. Then the micronized cassava starch has also been modified using a dry-method to improve its hydrophobic property, with aluminate coupling agent (ACA). The results suggest that the granularity of the starch decreases sharply through micronization in the vacuum ball-mill. The d ₅₀ value of micronized starch was reduced from 24.0 μm to 7.9 μm with the milling time from 0 h to 54 h. The active sites increase as the size of the cassava starch is reduced. The micronized starch has been found to be more easily gelatinized, dispersed in organic solvent and modified. The gelatinization temperature of starch was reduced from 59°?C to 23°?C with the milling time from 0 to 54 h.     

不同粉路中的小麦粉及其淀粉性质测定

研究了1T下、3M下、1Sf小麦粉及其淀粉的性质,测定了其淀粉、蛋白质、灰分、水分以及直链淀粉的含量,并对淀粉的粒径分布、溶解度和膨润力以及淀粉糊的透明度、冻融稳定性等特性进行了分析。实验结果表明:在小麦胚乳结构中,越接近麦心的部位,淀粉和直链淀粉含量越高,水分和蛋白质含量越低,灰分的差异不大;淀粉颗粒的大小顺序为3M下>1Sf>1T下,粒径呈正态分布;小麦淀粉随温度的升高,溶解度增大,膨润力上升;小麦淀粉糊的透明度较高,冻融稳定性较差。     

冷链米饭多尺度结构的变化及慢消化淀粉形成机制

研究利用体外消化方法证实短期冷藏（1 d）明显提升了米饭中慢消化淀粉的含量（达40%左右）。由小角X射线散射等多尺度结构的分析结果可知,短期冷藏过程显著降低了米饭中微米尺度孔隙的尺寸,并诱导分子链段重组装形成规整程度较低的短程螺旋、长程淀粉晶体和非周期性纳米结构,由此促进了米饭中慢消化态结构域的形成。然而,延长冷藏时间则增加非周期性结构等不同尺度结构的规整程度,致使部分慢消化淀粉转化为抗消化组分,但未明显改变米饭淀粉的其他消化特性。     

小米粉RVA糊化特性的研究

采用快速粘度分析仪（Rapid Viscosity Analyser,RVA）测定了在不同浓度、pH及添加蔗糖、食盐、明矾、硬脂酸等条件下小米糊RVA粘度曲线的变化情况,研究了小米淀粉粘度性质及其影响因素。结果显示,浓度对小米糊粘度性质影响显著,随浓度的增高,糊化温度降低,粘度曲线中峰值粘度及最终粘度升高;pH值对小米糊粘度性质影响较大,过高或过低的pH都会导致峰值粘度降低;随蔗糖添加量的增加,糊化温度略有增高;随着氯化钠浓度的增加糊化温度升高,氯化钠可提高小米糊粘度;明矾对小米糊的峰值粘度影响较大,而对糊化温度影响不大;添加硬脂酸的小米糊的最终粘度显著提高,而峰值粘度变化较小。通过研究为进一步了解小米淀粉的粘度特性及产品开发提供理论依据。